Subject: [PATCH v6 09/14] Remove table_scan_bitmap_next_tuple parameter tbmres

From: Melanie Plageman <[email-masked]>
Date: Mon, 12 Feb 2024 18:13:41 -0500

With the addition of the proposed streaming read API [1],
table_scan_bitmap_next_block() will no longer take a TBMIterateResult as
an input. Instead table AMs will be responsible for implementing a
callback for the streaming read API which specifies which blocks should
be prefetched and read.

Thus, it no longer makes sense to use the TBMIterateResult as a means of
communication between table_scan_bitmap_next_tuple() and
table_scan_bitmap_next_block().

Note that this parameter was unused by heap AM's implementation of
table_scan_bitmap_next_tuple().

[1] https://www.postgresql.org/message-id/flat/CA%2BhUKGJkOiOCa%2Bmag4BF%2BzHo7qo%3Do9CFheB8%3Dg6uT5TUm2gkvA%40mail.gmail.com
---
 src/backend/access/heap/heapam_handler.c  |  1 -
 src/backend/executor/nodeBitmapHeapscan.c |  2 +-
 src/include/access/tableam.h              | 12 +-----------
 3 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 10c1c3b616b..a1ec50ab7a8 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -2248,7 +2248,6 @@ heapam_scan_bitmap_next_block(TableScanDesc scan,
 
 static bool
 heapam_scan_bitmap_next_tuple(TableScanDesc scan,
-							  TBMIterateResult *tbmres,
 							  TupleTableSlot *slot)
 {
 	HeapScanDesc hscan = (HeapScanDesc) scan;
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 248ff90904b..04ad14f70b3 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -287,7 +287,7 @@ BitmapHeapNext(BitmapHeapScanState *node)
 		/*
 		 * Attempt to fetch tuple from AM.
 		 */
-		if (!table_scan_bitmap_next_tuple(scan, tbmres, slot))
+		if (!table_scan_bitmap_next_tuple(scan, slot))
 		{
 			/* nothing more to look at on this page */
 			node->tbmres = tbmres = NULL;
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index f1d0d4b78e3..e35bd36e710 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -787,10 +787,7 @@ typedef struct TableAmRoutine
 	 *
 	 * This will typically read and pin the target block, and do the necessary
 	 * work to allow scan_bitmap_next_tuple() to return tuples (e.g. it might
-	 * make sense to perform tuple visibility checks at this time). For some
-	 * AMs it will make more sense to do all the work referencing `tbmres`
-	 * contents here, for others it might be better to defer more work to
-	 * scan_bitmap_next_tuple.
+	 * make sense to perform tuple visibility checks at this time).
 	 *
 	 * If `tbmres->blockno` is -1, this is a lossy scan and all visible tuples
 	 * on the page have to be returned, otherwise the tuples at offsets in
@@ -821,15 +818,10 @@ typedef struct TableAmRoutine
 	 * Fetch the next tuple of a bitmap table scan into `slot` and return true
 	 * if a visible tuple was found, false otherwise.
 	 *
-	 * For some AMs it will make more sense to do all the work referencing
-	 * `tbmres` contents in scan_bitmap_next_block, for others it might be
-	 * better to defer more work to this callback.
-	 *
 	 * Optional callback, but either both scan_bitmap_next_block and
 	 * scan_bitmap_next_tuple need to exist, or neither.
 	 */
 	bool		(*scan_bitmap_next_tuple) (TableScanDesc scan,
-										   struct TBMIterateResult *tbmres,
 										   TupleTableSlot *slot);
 
 	/*
@@ -1988,7 +1980,6 @@ table_scan_bitmap_next_block(TableScanDesc scan,
  */
 static inline bool
 table_scan_bitmap_next_tuple(TableScanDesc scan,
-							 struct TBMIterateResult *tbmres,
 							 TupleTableSlot *slot)
 {
 	/*
@@ -2000,7 +1991,6 @@ table_scan_bitmap_next_tuple(TableScanDesc scan,
 		elog(ERROR, "unexpected table_scan_bitmap_next_tuple call during logical decoding");
 
 	return scan->rs_rd->rd_tableam->scan_bitmap_next_tuple(scan,
-														   tbmres,
 														   slot);
 }
 
-- 
2.40.1

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	filename="v6-0010-Make-table_scan_bitmap_next_block-async-friendly.patch"